1. Field of the Invention
The present invention relates to a conductive bridging random access memory (CBRAM) device and a method of manufacturing the same.
2. Description of Related Art
A CBRAM applies a non-volatile memory technique by which data accessing is performed according to a resistance variation. The CBRAM is belonged to a resistive random access memory (RRAM). A device structure of the CBRAM can be regarded as an electrolyzer composed of a metal anode (Ag or Cu), an inert cathode (Ni, W or Pt) and a solid electrolyte filled there between. A material of the solid electrolyte is glass-state chalcogenide or glass oxide. After a tiny voltage is applied between the anode and the cathode, an oxidation reaction is occurred at the anode, so that the metal on the surface of the anode releases electrons, and is dissolved into the electrolyte in an ion state. Due to an electrical migration, the metal ions are migrated towards the cathode. Finally, a reduction reaction is occurred on the surface of the cathode to precipitate conductive metal atoms and further form filaments, so as to decrease a whole resistance of the electrolyte to complete a write operation. Conversely, during an erase operation, the voltage is inversely applied to the electrodes, so that the filaments formed by the conductive metal atoms in the electrolyte are removed, and the resistance is gradually increased back to an initial state.
Regarding an oxide variable resistor having a bi-stable resistance switching, a low resistance path thereof (the filament) is a key to determine the resistance switching, and the metal filament is the low resistance path in the CBRAM. After an endurance test of the high-low resistance state conversion is performed to the device for tens of thousands of times, cycling times of the device and a switching time of the high-low resistance state conversion are probably reduced due to a quantity and distribution range of the filaments in the solid electrolyte.